


the waves hold your light

by laikaspeaks



Category: Rapunzel's Tangled Adventure (Cartoon)
Genre: Alternate Universe - Creatures & Monsters, Alternate Universe - Pirate, F/F, Human/Monster Romance, Rough Kissing, Sirens
Language: English
Status: Completed
Published: 2020-10-27
Updated: 2020-10-30
Packaged: 2021-03-09 05:22:13
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,216
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27229543
Author URL: https://archiveofourown.org/users/laikaspeaks/pseuds/laikaspeaks
Summary: As the daughter of a sailor Cassandra has spent most of her life on the sea, and she is well aware of its dangers... but she's on an island. What are the odds of her running into those dangers here?
Relationships: Cassandra/Rapunzel (Disney: Tangled)
Comments: 36
Kudos: 122





	1. Chapter 1

Cassandra didn’t spare the island a parting glance before she lowered herself down the side of the cliff to a ledge below. She knew what she would see - the slope of the mountain leading down to the sea, her ship floating in the harbor with the tiny figures of men moving to and fro on the shore. Between her long dark hair and dark clothes it was unlikely anyone would see her from the below. The blue sash she usually wore at her waist was tucked away into her small pack, and there was no reason for anyone to be looking up at the mountain anyway.

At least that’s what she told herself. 

Her goal was a few more blind drops down, a painfully narrow, winding path of stone that she had to shuffle down sideways to travel. It was a long trek, but the ship would remain moored at the island for a few days. She had the time and more importantly she needed a few hours off the close quarters of the ship. Gradually the little trail widened and gave way to sparse sand, then to grass, and finally brush and a few stubborn palms.  
  
If another person ever found this place she would be surprised. The floor of the crater was invisible from the lip, would anyone else bother with the long, long climb down?The mountain used to be a volcano according to the stories, but the sea flooded in through some long-ago fissure in the earth. Instead the inside of the mountain was now a miniature beach, a sheltered cove that Cassandra discovered during one of their regular stops on the island.

Except there were more ways in than from the top… and apparently someone else came here to enjoy the quiet.

The siren’s tail was impossible to miss - about six times as long as a human and a bright, vibrant yellow like the memory of every golden thing gathered in one place. The tail of a great serpent rather than a fish. A tropical siren this far from the equator? Cassandra had never heard of one wandering this far and certainly hadn’t seen one, but it was the middle of the summer. Perhaps that was the reason?

Cassandra caught smaller details in fleeting glimpses: Her upper body could be any girl, maybe three or four years younger than Cass. Chin length, sun-bleached hair and large green eyes. She was transfixed watching that streak of yellow race back and forth. Cass knew the danger - the siren was silent but that didn't mean she would _stay_ that way - but she couldn't bring herself to cut the moment short. She was certain she would never see anything like this again.

The moment the singing started - sweet and soaring, a dozen voices layered together into one like the blade of a master sword - she knew she was doomed. Then it didn’t matter. She was carved down to the way the song vibrated through her bones. The walls of the volcano sent the voice bouncing back in on itself, the siren a singer in her very own opera house. Cassandra didn’t even realize she was moving closer until she was ankle-deep in saltwater, staring down into a pair of the most beautiful eyes she had ever seen.

Up close the girl was stunning. All large, expressive green eyes and a full mouth. Full of _teeth_ when she smiled. Her face framed with a crest of delicately golden fins at the corners of her jaw. There was a little nick of a scar over her bottom lip, and somehow that made her seem more human than anything else. The siren pushed up on her coils to lean closer, her voice rhythmic with a language Cassandra couldn’t understand. But the song was like a child plucking at her sleeve. Eager, curious, wanting to know - to know -

Cass pointed to herself and said as clearly as she could. “Cassandra.”

How could she explain how trust was instantly forged? In the siren’s mouth her name was the first thread of a tapestry, the first strains of a full, rich song that was for her ears alone. _You, you, you_ laced into her name, filled with such delight in _her_ that she could only smile. If only she could listen long enough - if only she could hear the end of the song. When Cassandra was young she used to lie in her hammock below decks and listen to the sirens sing to each other in the dark... but it was different up close. The song took command of her senses and made her feel things, see things. She could understand why sailors died with it in their ears. That thought hit her like a splash of cold water. The thread snapped. 

She should leave now, before her father noticed she was gone. Or worse, resupplied and waited fruitlessly for her return, because his only daughter was murdered and eaten by a siren.

“Look… you’re real cute and all, but I have to go. See you around.” Some traitorous part of her almost wished that were true as she backed away a hesitant step.

The melody that pulled her in the first time was gentle as drifting in the shallows, still herself even if she was moved by something on the outside. What came tearing out of the siren’s body was like straying into the undertow, getting yanked below the surface until her lungs filled with water. The illusion of humanity stripped away for a scream that ricocheted off the walls like a musket ball.

 _Stay, stay, stay,_ edged with terror that lanced through her like lightning. 

She came back to her senses flat on her back in the sand. The siren haloed in sunlight, babbling staccato apologies. Cassandra couldn’t say what expression crossed her face… but it prompted the siren to slap both hands over her own mouth and fall silent for the first time since the singing started.

If it were anyone, anything else Cassandra’s fragile trust would crumble. Yet - she could feel the genuine remorse in the siren’s apologies, etched in the air as solid as something she could touch. There was a desperation that clawed at something deep and familiar and animal in Cassandra’s chest. She ran a hand down her face, trying to quiet her heart drumming against her ribs. It took a few false starts, but she got to her feet with a few helpful nudges from the siren. “What’s wrong? No - don’t say anything. Just show me.”

The siren grabbed her sleeve and pulled her down to the edge of the water, but rather than dragging Cassandra to a watery grave she only pointed, peering up at Cassandra with a furtive hope. Between the distortion of the water and the glaring sunlight Cassandra could only just make out carved stone pillars and an arch. An old, old doorway. There were tree trunks and scraps of old ships crammed into the opening, washed in by a recent storm and then pulled firmly into place as the tide went out.

Suddenly the siren's previous silence, her desperate darting around the crater made more sense. Cassandra's stomach sank. So she was trapped here? How long could something like her survive without food? Could she even climb out on her own? A sidelong glance confirmed what Cass feared… the siren looked grim as anyone would be staring down the barrel of starvation.

Damn, she really was an idiot.

Cassandra pointed aggressively, doing her best to get as much as irritation she could across when her knees were still shaking. “Let’s make one thing clear, princess. If you do that to me again, we’re going to have a problem. You got me?”

The siren nodded almost comically quickly, sitting up straight with her golden coils pulling up under herself neatly. The position somehow reminded Cassandra of a well-behaved puppy. 

Before she could talk herself out of it Cassandra waded into the water and lowered to one knee, instantly regretting the action when saltwater flooded her boots. "Climb on, princess. I'll get you out of here."

She knew in some abstract way that it would be so easy for the other girl to drown her here. They were far from anyone that could hear, and the water was easily deep enough for that. The fact was only driven home when the siren's heavy coils wound around her waist, all solid muscle and careful restraint. Forget drowning, she could easily be crushed to death. She stood and nearly stumbled at the full weight of the siren.

All that was wiped away with the soft trilling against the back of her neck. The song thrummed underneath, returned to that gentle tidal pull without taking her over the way it did before. _Thank you, thank you, thank you_ , a gratitude like breaching the surface after too long underwater, that first heave of air rushing into Cassandra’s lungs.

"You're welcome,” she said weakly. 

Well, her dad may have raised a fool but he didn’t raise a quitter. She straightened under the weight and started up the narrow trail that marked the first leg of their journey. The climb was brutal even without the extra weight, and what an extra burden the siren made. Not only was she solid muscle, but she couldn’t seem to sit still, craning her neck to exclaim over flowers, birds, leaves, and rocks like a child. 

It would be more endearing if they weren’t in danger of falling all the way back down into the crater. Fortunately the steeper parts of the climb did have ledges where she could stop and rest. Or more accurately, collapse and seriously question her choices. By the time they reached the rim of the volcano, she finally gave up on finding a moderately comfortable rock and flopped directly on golden coils, all fear lost after the thousandth interesting leaf shoved into her face.

“Yeah, yeah. That’s the best rock I’ve ever seen.” She grumbled, throwing an arm over her eyes to block out the sun. Eventually even the siren settled, and the breeze and the sound of gulls lulled her to such an extent that she didn’t even react to the gentle hands running through her hair. ...Until she felt a sharp poke at her cheek, and sat up with a startled yelp that made her companion giggle. 

_Silly,_ the siren laughed, her wry amusement painting the air.

Cassandra’s hand went up to her hair, and found that it was woven onto a braid around the crown of her head. Soft flower petals met her searching fingers as well. How deeply did she fall asleep anyway? And for how long? Yeah, she really had to look as stupid as she felt.

“Oh. Well. Thank you.” She ducked her head, hoping it would hide her burning face… but of course her hair was up now. 

And the siren clearly didn’t know or didn’t care she was trying to hide, because she ducked her head down to peer up into Cassandra’s eyes, smiling that razor-sweet smile. She hummed brightly, strains of her meaning twining themselves into the air: _pretty, pretty, pretty._

“Thanks,” Cassandra croaked again, certain she was about to faint from all the blood rushing to her head. She wiggled free of the siren’s embrace and shielded her eyes to get a better look at the darkening sky. “Fuck, we’re running out of time, princess.”

She scooped the siren up in her arms, and was gratified to see the other girl’s cheeks color. It actually took a long moment for her to start out of her daze and wrap around Cassandra once more. Cute. 

“It’s not far now. If we hurry -”

“Cassandra!” Called a voice.

“Cass!” Came another.

“Where are you?” Shouted a third.

There were torches moving on the mountain. Her thoughts slowed to a crawl, so Cassandra had a long fraction of a second to see the abject terror cross over the siren’s face. That was the last thing she saw before the serpent flung herself away from Cass. The force was enough to throw her off balance and send her face rushing to meet volcanic rock.

Then she didn’t see anything at all.

When she opened her eyes next they met familiar rough-hewn beams overhead, the creak and sway of her hammock revealing her location before she thought to ask the question. Her father leaned into her line of sight, his weathered face dark with disapproval. Everything Cassandra did and saw slammed face-first against a reality that couldn’t coexist with what happened. Was it a dream? It had to have been a dream.

“Where have you been, whelp?”

“Out,” she growled back, forcing herself to sit up and nearly heaving at the way the world swiveled loosely around her movements.

“We found you in the woods on the mountain, looks like you slipped and fell.” He didn’t say a word about her tone but he didn’t need to with that sharp look. “What were you even doing, wandering off when you should have been helping? We lost a lot of time looking for you."

“Walking.” 

A little, rebellious flame of anger flared up in her chest. How dare she get hurt? How dare she trouble him in any way? It wasn’t as if the others didn’t get shore leave. Why was she the one expected to stay behind? Even if she could understand logically - the captain couldn’t look soft on his daughter - it still burned. That train of thought was cut off by his next question. 

“And what did you do to your hair?”


	2. Chapter 2

Cassandra wished she was smart enough to ditch this shitshow when she had the chance. 

Eugene and Lance disappeared a full three ports ago, and she was too stubborn to admit that she was wrong. Really, Stalyan jumping ship at the last port should have been her final warning. The Baron was objectively a monster, and too proud to admit that he was wrong either. Which was how they ended up in the middle of this raging storm, a siren song rising loud enough to drown out the wind. 

Cassandra clung to the top of the mast, hoping against hope that distance would give her a chance. Every time the ship rocked in the water it flung her through the stinging rain so quickly that it felt like she was going to be sick, but she didn’t dare let go. 

The others were long gone. She wasn’t strong enough to hold even one of them back. As much as she hated every one of the remaining crew she at least owed them the attempt. 

If she hadn’t heard the song up close before she would already be in the water. Even now, with the terror pumping through her veins, she could feel the dozens of voices prying at her brain. Their voices were so sweet and curious, so welcoming. If she didn’t know what the real thing sounded like - but she did. No matter how their song glittered, no matter what it promised, she could sense the dark hunger moving beneath. 

If the sea had a voice she must sound like a siren.

Of course, Cassandra couldn’t struggle forever. Eventually her thighs started to burn, and even the cold rain couldn’t quite ice away the pain in her stiff fingers. Eventually the ship bucked hard enough to send Cass flying like a stone from a sling. The impact knocked the air from her lungs and stunned her to stillness, drifting down, down, her eyes adjusting to the salt-sting and darkness faster than was merciful. The sirens circled around the ship in a whirlpool of silken color, darting and interweaving in a mirror of their song.

One broke away from the feeding school and dove after Cassandra with unexpected urgency.

 _It’s you._ She thought.

Her siren stood out stark against the others. Her bright scales seemed to draw in and amplify the threads of moonlight, and as she drew closer Cassandra realized the siren must be easily twice larger than her sisters. Somehow Cassandra had pictured her the same, but she had also grown over the years. 

She must have imagined the concern.

Part of her didn’t want to believe it even as that shining body twined around her, cinching around her waist firmly as the siren did on that mountain years ago. Dragging her deeper. If she could reach the surface on the air she had, that chance faded along with the moonlight as they sank into the formless dark. Even the sound-vibration of the feeding sirens faded away to nothing.

Cassandra had spent most of her life working on ships, pulling heavy, wet ropes until her joints popped, slinging barrels of water and crates of food on her shoulders. If nothing else she was stubborn. She curled her fingers into claws and aimed for the eyes, determined to make the siren work for her meal. The siren snagged her wrists. If she weren’t holding on to that last, precious breath of air she would have howled with frustration.

She didn’t want to die like this - she didn’t want to die at all - but especially not like this. Not helpless in the dark. Not with those green eyes watching, mocking one of her most treasured memories.

Those strong hands pried her arms further apart, allowing the siren to press closer, twining more tightly. Holding her still. She snapped at the siren’s face with the last of her strength, barely registering the last bubbles of air slipping between her teeth.

Then a warm mouth settled over Cassandra’s, chaste and sweet and utterly destroying any conscious thought.

She blamed the lack of oxygen for what happened next, because she pressed into the kiss. Slid their mouths together the way she imagined many times after that brief afternoon, before she decided she had to grow out of the world’s most self-defeating, one-sided crush. There were women after that, of course there were, but -

It wasn’t the same.

Her back hit sand, and she felt rather than saw the silt rise up in a cloud on impact.

Whatever the hell was going on, holding back was a waste of her very limited time. She twined her fingers into the siren’s hair and coaxed her closer. The strained noise the siren made against her mouth in response had to be on accident. It was too revealing, too flustered, her voice edged with the same kind of promise as a hand sliding up Cassandra’s ribs. So Cass understood with embarrassing clarity what drove the siren to draw back and rasp her teeth delicately over the pulse in her throat. And it wasn’t the kind of hunger that scared her at all.

It was the first time the siren made a sound since she appeared, Cassandra realized dimly. It wasn’t the tugging, demanding song she remembered and not a terrifying command. 

She tried to lean up for another kiss, but the siren tightened her coils around Cassandra’s hips and legs, using the leverage to force her hands to either side of her head. She could feel the shudder that ran through the other woman, the breathless noises that couldn’t travel through water but she could feel through her body where they touched.

“Wow, okay that’s - can you understand me now, Cassandra?”

The siren let go of her hands and instead her touch wandered to Cassandra’s cheeks, brushing her hair out of her face. Cassandra knew she wasn’t imagining the tenderness because the siren’s voice had in no way lost its magic. There was a sweet melody to her words, and a thinly veiled undercurrent of desire that sent sparks of heat flickering up and down Cassandra’s spine.

“Am I dead?” Cass _breathed_ , half hoping that she didn’t actually survive the stupid fucking thing she just did.

“I hope not.” The siren laughed. Her hand smoothed down the back of Cassandra’s neck. “I worked really hard to keep that from happening you know. You hit really hard, by the way.”

“Sorry.” Shit. She really did survive, and now she was gonna have to die. Cassandra was almost pathetically grateful for the darkness right up until she realized that the siren could probably see in the dark. 

“No, I’m… I’m really sorry, Cassandra. I didn’t mean to scare you.”

“I wasn’t scared.”

“If you say so.” There was a breath of sadness in the siren’s voice, like winter chill creeping down the neck of Cassandra’s coat. 

“Okay. I lied. Of course I was scared. But it’s okay. You saved my life.” She felt around in the dark and managed to snag one of the siren’s hands. They were strong, which she expected, and had fine membranes between the digits, which she did not. “I would have drowned if you didn’t do… whatever it is you did. We both know that, right?”

“Yes. I didn’t have a choice.” 

Cassandra really didn’t like the way she said that.

“It’s called the Sailor’s Kiss.” The siren mumbled, her other hand settling over one of Cassandra’s. “It - well, it does this. Obviously you can understand me now, but you also can’t drown anymore. Even if you tried.”

“Anymore. Like, this isn’t gonna wear off?” She was almost disappointed given how sirens apparently handed this ability out. 

“It’s the kind of gift you can only give once.”

Fear lanced through Cassandra’s chest. “Are you dying?”

“What? No! It’s just… you can only do it once.”

“Why?”

“Don’t ask me that, please.”

“I’m asking.” Here she was so far underwater that she couldn’t even see, still somehow alive and blindly reaching out for more. For something. For the vain hope that all of this wasn’t just in her head. 

“...It’s a long story.”

“We have time. Unless you’re planning to swim me back to shore through that storm.”

The siren seemed to see her point, because she coiled up into a more comfortable pile. Which Cassandra only realized because she pulled Cass back into her eagerly, her song vibrating in her chest contented as the rasp of a whetstone on a blade.

“Well, it’s only a legend. But the stories say that the sea herself fell in love with a sailor, who was her equal in every way. Too strong and fierce and beautiful for a human lover. And she loved the sea in the only way anyone can - they fought long and terribly, and each time the sailor escaped with her life.”

“Why do I feel like there’s a “but” incoming?”

She could almost feel the siren smile.

“But one day the sailor’s ship smashed against the shore. And the sailor’s blood…”

“Created the first sirens. Yeah, I know the story.”

“You tell the story too?” The siren hummed, a flicker of amusement flitting between them delicate as a fish.

“According to _our_ story,” the siren continued, her hands smoothing down Cassandra’s face, her neck, her shoulders, skimming down the full length of her body, and Cassandra never wished more desperately that she could see someone’s expression. She had a feeling whatever she would see in the siren’s eyes would ruin her, and she would love every second of it, “She created us, her many daughters, to be her love. We’re still of the sea, but we’re also… a little human. Enough that we can love you without destroying you.” 

“That sounds a little different from what I just saw up there.” Somehow that story was softer than she expected. It was easier to imagine blood and hunger being behind the siren’s creation than love.

“Just because we _can_ doesn’t mean we _do_.”

Those words dropped to a dark purr, and Cassandra felt it as the siren felt it - the electric joy of the hunt, the tendrils of satisfied justice. She was reminded of those beautiful creatures circling in the dark, their voices raising and falling like the waves. Evidently she was quiet for too long, because the siren shifted and let out a slow breath. 

“But I do.” Those words were empty of any additional melody, any special weight beyond their meaning. “You saved my life. You were my hero, when I didn’t - didn’t have anyone like that for a long time.”

“I didn’t do this to force anything on you, Cassandra. It doesn’t have to mean... anything.” Despite the way she said that she curled even closer, her hands wandering in a way that was surprisingly chaste. As if she remembered that she couldn’t keep Cassandra, and wanted to remember as much as she could. 

She sounded so defeated. So certain of the outcome to all this.

The girl that Cassandra rescued brimmed with the simple joy of being alive. She wondered what burdens the siren carried since then to make that joy falter, what circumstances led her to being trapped in that mountain. What she thought, and felt. What songs she sang when she was alone with no one to feel what her voice carried. She wanted to know the woman, not just remember the girl.

“What’s your name?”

“Hm?”

“You never told me. Your name.”

“Rapunzel.”

Cassandra snorted. “Like the cabbage?”

“Oh - what’s a cabbage?” Rapunzel crowded close enough that Cassandra could see the faint glow of her pretty green eyes. “Tell me about it.”

And she did.

**Author's Note:**

> This is a little bit me experimenting with some stuff so it may be shaky at some points. I hope you still enjoyed it!


End file.
